Valve device



s. M. DUNN VALVE DEVICE v Filed Feb. 13. 1939 Patented July 1, i941 tiNlTED STATES 18 Claims.

My invention relates to valve devices for the control of fluid flow, and particularly to a check valve.

An object of the invention is to provide a valve which seals tightly in the closed position closure is effected by a collapsible flexible sleeve member in sealing contact with a central core, and in which, in the closed position of the valve, the flexible sleeve member is maintained in tension to tightly hold it in sealing contact with the core Another object is to provide a check valve which will promptly close upon decrease of fluid pressure on its inlet side.

A further object is to provide a valve device adaptedto close automatically upon a predetermined variation in the pressure differential on the fluid flowing through the valve device. Another object is to provide a check valve which may be adjusted either to open or to remain closed when a sudden pressure surge in the outlet line occurs while the valve is in a closed position by reason of a higher pressure on its outlet side.

Still another object ,of the invention is provide a valve that is easy and cheap to construct, is convenient and eflicient in operation,

and is of long life.

These and other apparent objects I attain in a manner which will be clear from consideration of the following description taken in connection with the accompanying drawing, of which:

Fig. 1 is asectional view of the valve of my 1 invention.

Fig. 2 is a sectional view of the valve of Fig. 1 taken, along the line 2-2, as indicated. I

Fig. 3 is a sectional view of an alternative form of my valve.

Referring fQ the drawing, Figs. 1 and 2 show the first housing member at is provided with an outwardly directed flange l3, and supported on the interior of the first housing member I by a plurality of circumferentially spaced webs it, or otherwise, and axially aligned with the housing member is a central core l5. The central core is preferably a hollow closed body of "ellipsoidal form in its middle portion and extends to a point at both ends thereof to provide a streamline effect, although it will be evident that cores of other shapes may be used without departing from the spirit of the invention. The exterior of the central core l5 is preferably coated with a vitreous enamel or other smooth corrosion-resistant surface, although this provision may be omitted if desired. The space between the central core and the first housing member 111] forms an annular passage lt communicating with the inlet passage it between the webs it.

A flexible member ii is provided, forming the movable valve member of the invention, and is preferably made of rubber or other suitable resilient material, being reinforced for longitudinal tension by means of a plurality of strands or tapes it made of metal fabric, or other suitable reinforcing material embedded in or otherwise attached to the flexible member H. The tapes it are preferably circumferentially spaced from each other and are disposed longitudinally relative to the flexible member M. It will be understood, however, that the tapes it may be disposed along a slight spiral relative to the flexible member it if desired to take up additional slack in the flexible member, or may be dispensed with entirely under some circumstances Without departing from the invention. The flexible member El! is preferably of such construction that it offers substantially no resistance to bending and is such that longitudinal tension therein is substantially the only-force efiective in determining the shape of the flexible member.

The tapes l8 extend at one end through holes IS in a ring element 283 and are soldered or otherwise suitably secured relative thereto. The other ends of the tapes 58 pass through suitable holes in a flanged ring 2i and into holes 23 in a supporting member 22, and are soldered or otherwise secured to the supporting member in a such a mannerthat the flexible member H is commodate the ring 20. A second housing mem-- ber 38 is clamped by bolts 3! against the flange for the flexible element I! and a specially formed.

supporting member 22 therefor, it is to be understood that the flexible element may be anchored by any suitable construction, and that the supporting member may be dispensed with if desired, without departing from the spirit of my invention.

It will thus be understood that the flexible member I1 is preferably secured to the supporting member 22 at one end and that the other end thereof is preferably tightly clamped between the supporting member and the flange I3 of the first housing member by the clamping action of the second housing member 3|]. It is also to be noted that the flexible member H is of such length that when it is in collapsed position, as shown in Fig. 1, it is stretched tightly over an area of considerable axial width of the convex middle portion |5a of the central core IS in sealing contact therewith, and that when the flexible member ll is in expanded position, as indicated by the dotted lines Ila in Fig. 1, it rests snugly against the inner concave surface 22a of the supporting member '22. It will be apparent that the flexible member l1 may be provided with creasing the concavity of the inner concave surface 22a. of the supporting member 22, or by disposing the tapes la in a spiral direction relative thereto.

The second housing member is provided with a discharge passage 36 which communicates between the flexible member I! and the central core IS with the'annular passage I6, and through the latter with the inlet passage II, this communication forming the main valve passage of my invention. The second housing member 30 is also provided with a flange 3| suitably connected to discharge piping 38 which leads to a increased or decreased slack by increasing or depoint of disposal or discharge (not shown), and

has intersecting fluid passages 40 and 4| forming communication between the discharge passage 36 and a space 42 formed between the supporting member 22 and the second housing member 30.

The supporting member 22 is also provided with a plurality of apertures 43 communicating between the space 42 and a space 44 between the supporting member 22 and the flexible member IT. A valve element is threadedly received in the second housing member 30 and is axially aligned with the passage 40 so that by screwing the valve element toward or away from the passage 40 the fluid flow therethrough may be restricted as desired. If desired, a plurality of fluid passages similar to the passages 40 and 4| may be provided at circumferentially spaced locations around the second housing member 30, and a valve element similar to the valve element 45 may be provided to cooperate with each of such passages to increase the total cross-sectional flow area through the passages, which may be advisable in large constructions. While I prefer to form the passages." and directly in the secmunicating with the lower portion of the surge chamber 50 is a conduit 5| leading to the discharge piping 38. The conduit 5| is provided with a check valve 52,,of any type well known in the art, adapted to permit fluid to flow from the outlet piping 38 toward the surge chamber 50 but preventing a fluid flow in the opposite direction. A manually operated valve 53 is also provided in the line of the conduit 5|, by which an operator may open or closecommunication through the conduit as desired. The conduit 5|, and associated elements, may be entirely dispensedv with 7 if desired.

In operation, when it is desired to use the valve device 9 as a discharge check valve, the inlet piping |2ais connected to a suitable source of fluid under pressure, such as a centrifugal pump (not shown), and the discharge piping 38 is connected to a fluid system providing a fluid back pressure in the discharge piping. Assuming that the flexible member H is in sealing contact with the central core l5, so as to close the main valve passage, and the valve element 45 is adjusted so as to provide -fluid communication between the discharge passage 36 and the spaces 42 and 44 through the passages 40 and 4| and the apertures 43, the pressure exerted by the fluidin the space 44 against the back of the flexible member II will be equivalent to the fluid pressure in the discharge passage 36, which is greater than the pressure of the fluid in the-inlet passage II and the annular passage l6, and the flexible member will remain in sealing contact with the central core I5. Upon a suflicient rise in the pressure of the fluid in the inlet passage II and the annular passage I6, due to operation of the pump or other source of fluid under pressure, the fluid pressure in the annular passage l6 will overbal ance the fluid pressure in the space 44 and the flexible member will move outwardly toward the position shown in dotted lines Ila in Fig. 1 to permit the fluid to flow from the'inlet passage [I through the main vvalve passage to- .tion shown in the dotted lines |'|a in which it snugly engages the supporting member 22 to form a smooth wall of the then open main valve passage, which is an important feature of my invention as it reduces flow friction to a minim As fluid flow continues through the main valve passage, the fluid pressure within the surge chamber and the space 42 willgradually approach thes ame value as the fluid pressure in the discharge passage 36, the fluid pressures substan- Upon a drop in fluid pressure in the inlet pas-' tially equalizing-through the passages 40 and sage ll, due to a cessation in pumping or from any other cause, this pressure drop is communicated through the annular passage it to the fluid between the flexible member H and the core l5, and since equalization of fluid pressures between the spaces 4t and t2 and-the discharge passage it is retarded by the restricted communication therebetween controlled by the setting of the valve element 415, the fluid pressures acting on the inside and outside of the flexible mmber ll immediately become substantially unbalanced, with a relatively high fluid pressure in the space M and a relatively low fluid pressure in the main valve passage. Relatively high fluid pressure in the sure to be applied to the entire external surface of the flexible member. This unbalance of fluid pressures acting on the flexible member li immediately contracts the flexible member into sealing engagement with the central core l5, placing the flexible member in tension and forcing it into pressure engagement with a considerable axial area of the middle portion 55a of the central core. It is to be noted that, when the flexible member I1 is in sealing contact with the central core it, the flexible member forms a double or S-shaped curve, the inlet end thereof forming an inwardly convex curved surface of short radius A and the portion thereof in em gagement with the central core forming an inwardly concave curved surf-ace of long radius R in contact with the central core E5.

The pressure with which the flexible member H is held in pressure engagement with the central core I5 is a function of the radii A and R, v

and the fluid pressures exerted on the flexible member, and the relationship of these variables The above formula is basedon the assumption that the length of the arc of the flexible member ll, defined by the radius A, is 90 degrees and that this are is tangent to the spherical middle portion 55a of the surface of the central core 55 on a great circle thereof. Therefore, when the flexible member it is in engagement with the core member l5, as shown in full lines in Fig. 1, the curved portion of the flexible member having the radius A is subjected to a pressure differential of P1P2, and each element of the area of the curved portion is subjected to an inwardly acting radial force dependent on the intensity of the pressure differential Pl-P2. Since the member ll is flexible and is supported only at its ends, the summation of the force components-in the radial direction of all forces acting on the flexible member, referring to radial direction in the sense of the radius of the valve device as a whole, will be resisted bythe force reaction at the anchorage thereof at the inlet direction is:

end of the flexible member, and the s w: a: tion of 'the force components in an axial direction acting on the flexible member will be resisted by the force reaction at the anchorage thereof at the outlet end. These reactions will be equal to each other and to the tension in the flexible member ll.

Obviously, the summation of all of the forces acting on the total area of the curved portion of the flexible member having the radius A is equal to the area of the projection of the curved portion on a plane normal to the axis of the valve device multiplied by the pressure difl'erential thereon. The inner and .outer radii of this projected area will be R and R+A. respectively, and the area will be:

which equals:

' 1r(2AR+A The total force or tension acting in the'axial Thetension per unit of width or the flexible member is:

Since the sealing force or bearing pressure of theflexible member tl against the portion a of the core member iii is due to the tension and:

in the flexible member ill, it is obvious that the bearing pressure P may be obtained by equating the expressions for unit tension in the flexible member and the wall tension ina sphere, and solving for P, Thus:

It will thus be evident that the sealing pressure with which the flexible member it is held in engagement with the central core l5 may, by a suitable choice of relative dimensions of the parts, be made relativelygreat and entirely adequate to maintain the flexible member l l! in pressure engagement with the central core it against the action of the fluid pressure exerted by the fluid in the discharge passage 36. It will also be evident that, due to this mode of operation, my valve device 9 will satisfactorily operate as a check valve in any fluid flow line to prevent a reversal of flow of fluid upon a decrease in pressure in the supply end of the line under thepressure in the outlet The valve may be adjusted either to open or to remain closed when a surge in pressure occurs in the outlet piping 38, depending upon the ad-.

justment of thevalve 45 and whether the valve 53 is closed or open. If the valve 53 is closed.

and the valve 45 is in a position to restrict flow through the passages 46 and M, as in the operation above described, and a surge takes place in .the outlet piping 38 resulting in a greatly increased pressure in the outlet passage 36, it will beimpossible for the increased pressure to immediately exert itself in the space 44 outside'the established between the surge chamber 56 and theoutlet piping, and the increased pressure due to the surge can then exert itself on the outside of the flexible member]! by way of the valve 53,

the check valve-52, the conduit 5|, the surge chamber 50, the opening 48', and the apertures 43. Under these circumstances, the increased differential pressure between the space 44 and the passage I6 will hold the flexible member II in sealing contact with the core l5 against the increased pressure in the outlet passage 36, and the valve will remain closed.

In the alternative embodiment of my invention illustrated in Fig. 3, in which similar parts are given the same numerals as in Figs. 1 and 2, no surge chamber is employed and no connection. between the space 44 .and the outlet passage 36 is provided except through the passages 40 and 4|, which in this embodiment are preferably larger in cross section than the corresponding passages in the embodiment of Figs. 1 and 22. In

the form of the device illustrated in Fig. 3, a Valve element may be provided toregulate the flow through the passages 40 and 4|, but the valve element 45 is preferably adjusted to a wide-open position.

In the operation of the valve device illustrated in Fig. 3, it will be evident that if the flexible member IT is in the closed position illustrated in solid lines, and fluid pressure is applied in the annular passage-l6 by reason of the starting of a pump connected to the inlet, the flexible member I1 will be forced away from the centralcore i5 and back'into its open position indicated in dotted lines, exactly as described above in connection with the operation of the embodiment shown in Figs. 1 and 2. As the flexible member I1 is moved from its closed position into theopen position shown in dotted lines Ha, the fluid in the space 44 is forced through the apertures 43 into the space 42 and out through the passages 40 and 4| into the discharge passage 36. If the fluid pressure in the annular passage l6 should drop due to the stopping of the'pump or for any other reason, the tendency is for the flexible member I! to be forced into the closed' position. It is desirable that unrestricted communication exist between the space 44 outside of the flexible member l1 and the discharge passage 36 in order that all of the pressure of the fluid in the discharge passage 36 may be available to force the flexible member I] to its closed position; Should the flexible member ll'l not close'immediately and fluid pass in a reverse direction through the mainyalve passage, it will be evident that the pressure of the fluid in the annular passage I6 will, by reason of the pressure drop in the valve, be less'than the pressure of the fluid in the ,dischargepassage 36 and in the space 44. This differential pressure will cause the movement of the flexible member I'I toward the closed position, and, as the flexible member ll approaches the closed position, the pressuretightly over the convex middle portion l5a of the central core l5 to produce a tight sealing contact therewith.

It will be understood that the valve device of my invention may be employed to control the flow of fluid in fluid systems difierent from that disclosed herein, and that the design and construction of the valve device and the size and shape of the various parts thereof may be changed within wide limits without departing from the spirit and scope of the-invention as defined in the appended claims.

I claim as my invention:

1. In a valve device, the combination of: a housing having a fluid passage therethrough; a collapsible flexible sleeve in said passage adapted when collapsed to shut off the flow of fluid through said passage, said sleeve normally being expanded outwardly during fluid flow through said passage; surge chamber means; fluid connections connecting said surge chamber means with the outlet of said passage and with a chamber surrounding the outside surface of said sleeve, whereby fluid pressure from said surge chamber means is available for collapsing said sleeve; and valve means in the fluid connection connecting said surge chamber means with said passage outlet whereby to selectively restrict fluid flow between said surge chamber means and said passage outlet.

2. In a valve device, the combination of: a housing having a fluid passage therethrough; a collapsible flexible sleeve in said passage adapted when collapsed to shut off the flow of fluid through said passage, said sleeve normally being expandd outwardly'during fluid flow through said passage; surge chamber means having a fluid connection with a chamber surrounding the outside surface of said sleeve; a restricted fluid connection between the outlet end. of said passage and said chamber surrounding saidsleeve; and a check-valved fluid connection between said surge chamber means and the outlet end of said passage, said check-valved connection being adapted to permit flow of fluid from said outlet end of said passage toward said surge chamber means.

3. In a valve device, the combination of a housing having a wall forming a fluid passage wardly expanded position substantially conforming to the shape of said concave portion of said .wall of said passage and in the closed position of said valve device to be heldin sealing contact with said core; and means for conduc'ting fluid under pressure to the outside surface of said sleeve to move said sleeve to said closed posiwardly concave from the center of said passage; a

core member located within said passage opposite to said concave portion of said wall and presenting a convex outer surface; ,a flexible sleeve in said housing and anchored at both ends in such manner as to provide slack in saidsleeve, said sleeve being adapted in the open position of said valve device to assume an outwardly expanded position substantially conforming to the shape of said concave portion of said wall of said fluid passage and in the closed position of said valve de vice to be held in sealing contact with. said convex surface of said core by reason of the tension in said sleeve caused by the difference in pressure on the two sides of said sleeve; and means for conducting fluid under pressure to the outside surface of said sleeve to move said sleeve to closed position. g

5. .In a valve device, the combination of a housing having a wall forming a fluid passage therethrough, a portion of said wall being outwardly concave from the center of said passage; a core member located within said passage opposite to said concave portion of said wall; a flexible sleeve in said housing and surrounding said core member, said sleeve being substantially longitudinally non-extensible and anchored at both ends in such manner as to provide slack in said sleeve, said sleeve being adapted in the open position of said valve device to assume an outwardly expanded position substantially conforming to the shape of said concave portion of said wall of said fluid passage and in the closed position of said valve device to be held in sealing contact with said core member by reason of tension in said sleeve caused by a difference in fluid pressure on the two sides of said sleeve; and means for conducting fluid under pressure to the outside surface of said sleeve to move said sleeve to said closed position.

6. In a valve device, the combination of: a housing providing a fluid inlet, a fluid outlet, and a fluid passage through said valve device, said fluid passage having an outwardly concave portion; a core member located within said passage opposite to said concave portion of .said fluid passage and presenting a convex outer surface; a flexible sleeve anchored at both ends in said housing in such manner as to provide slack in said sleeve, saidsleeve being adapted in the open position of said valve device to assume an outwardly expanded position substantially conforming to the shape of said concave portion. of said fluid passage and inthe closed position of said valve device to be held in sealing contact with said convex surface of said core member by reason of tension in said sleeve caused by a difference in pressure on the two sides of said sleeve, said sleeve ofiering substantially no resistance to bending and being of such character that longitudinal tension is substantially the only force in said sleeve efiective in'determining the shape of said sleeve in the closed position; and a fluid connection between said fluid outlet and the surrounding surface of said sleeve.

7. In a valve device, the, combination of: a housing providing a fluid inlet, a fluid outlet, and a fluid passage through said valve device; a core member supported from sa'id housing and located within said passage and presenting a convex outer surface; a sleeve surrounding said core member and composed of resilient material having longitudinally disposed, substantially non-extensible reinforcement elements therein; and an apertured sleeve-supporting member surrounding said sleeve having an inner concave surface of substantially the same longitudinal length as said sleeve, the ends of said reinforcement elements being retained stationary relative to said sleeve-supporting member, said sleeve being adapted in the open position of said valve deviceto lie along the inner surface of said sleevesupporting member and in the closed position of said valve device to be held in sealing contact with said core.

8. In a valve device, the combination of: a housing having a fluid passage therethrough; a core member located within said passage; a flexible sleeve anchored at both ends in such man ner as to provide slack in said sleeve, said sleeve being adapted in the open position of said valve device toassume an outwardly expanded position to form a wall of said fluid passage and in the closed position of said valve device to be held in sealing contact with said core member by tension in said sleeve caused by a difference in fluid pressures on the two sides of said sleeve; an air chamber in fluid connection with the outside surface of said sleeve; and a restricted fluid connec-,

tion between said air chamber and the outlet end of said passage, said connection being adapted to convey fluid from said outlet into said air chamher so as to put the air in said air chamber under substantially the same fluid pressure as exists in said outlet.

-9. In a valve device, the combination of: a housing having a fluid passage therethrough; a core member located within said passage and having a convex outer surface; a flexible sleeve in said housing and anchored at both ends in such manner as to provide slack in said sleeve,

said sleeve being adapted in the open position of ,said valve device to assume an outwardly expanded position to form a, wall of said fluid pas sage through said valve and in the closed position of said valve device to be held in sealing contact with said convex surface of said core member by tension in said sleeve caused by a. difference in fluid pressures on the two sides of said sleeve; an

air chamber in fluid connection with the space surrounding said sleeve; a restricted fluid connection between said air chamber and the outlet end of said passage; and a check-valved fluid connection between said air chamber and said outlet end of said. passage, said check-valved connection being adapted to permit a flow of fluid from said outlet end into said air chamber.

10. In a valve device, the combination of r a housing having a fluid passage therethrough; a core member located within said passage and presenting a convex outer surface; a flexible sleeve surrounding said core in said passage, said sleeve being longitudinally non-extensible and anchored at both ends in such manner as to provide slack in said sleeve, and said sleeve being adapted in the open position of said valve device said sleeve, said sleeve being adapted in open position of said valve device to assumean outwardly expanded position substantially conforming to the shape of said concave portion of said well of said passage, and in closed position of said valve device to assume a contracted position to engage said core member in sealing contact therewith, said sleeve being adapted to be expanded and contracted by pressure differential of the fluid on opposite sides'of thesleeve.

12. In a valve device,'the combination of: a housing means having a fluid passage therethrough said fluid passage having an inlet and an outlet; a core member positioned in said passage, said core member having a convex outer surface; a flexible sleeve surrounding said core member in said passage, said sleeve being movable be-' tween an expanded position in which it forms a wall of said passage and a collapsed position in wnichit engages a substantial axial area of said convex surface so as to form a sealing engagement with said convex surface, said sleeve when in said collapsed position having another curved I portion not in engagement with said convex sur-;

face and curvedoppositely relative thereto; and means for introducing pressure fluid into engagement with the outer surface of said sleeve to hold said sleeve in said sealing engagement, the sealing force exerted by said sleeve on said core member being expressed by the formula (P, P (2AR+ A) P: R

in which P: unit pressure exerted by said sleeve on said core member, P1: the pressure of said pressure fluid engaging the outer surface of said sleeve, P2: the pressure of said pressure fluid in said inlet, R: the radius of said convex surface, and'A: the radius of said other curved portion of said sleeve.

13. A valve device having a core member and a flexible sleeve adapted to engage said core member in sealing engagement therewith so as to produce an S-curve in said flexible sleeve, only onehalf of said curve being in engagement with said core member, in which the sealing force, P, exerted by said sleeve on said core member is expressed by the formula P, P (2AR+ A) i It in which P1: fluid pressureon the outside of said sleeve, P2: fluid pressure in one end of said sleeve, R: the radius of said one-half of said curve, and A: the radius of the other half of said curve.

.14. In a valve device, the combination of a housing having a fluid passage therethrough; a

,core member located within said passage, a slack I core member, the curvature of said curved portion creating a sealing force in said sleeve tending to form a seal between said sleeve and said core member; and means for admitting fluid under pressure into a space in said housing surrounding said sleeve, the sealing force exerted by the combination of the tension in and the curvature of said sleeve in response to the pressure differential across said sleeve maintaining said sleeve in sealing engagement with said core member to prevent a flow of fluid through said passage.

15. In a valve device, the combination of: a housing having a fluid passage therethrough, said fluid, passage having a first end and a second end; a core member located within said passage intermediate said ends; a slack flexible sleeve in said housing and surrounding said core member, said sleeve being anchored at one of its ends adjacent said first end of said passage so as to form when contracted by fluid pressure a curved portion thereof extending convexly inwardly into engagement with said core member, there being an annular space in said housing around said sleeve member, the inward curvature of said curved portion of saidsleeve together with the tension in said sleeve due to pressure differential across said sleeve creating a sealing force in said sleeve tending toform a scalbetween said sleeve and said core member; and means for admitting fluid under pressure from said second end of said passage into said space, the sealing force exerted by the curvature of said sleeve cooperating with the pressure of said fluid in said space to maintain said sleeve in sealing engagement with said core member to prevent a flow of fluid through said passage from said second end to said first end thereof.

"16. In a valve device, the combination of: a housing having a fluid passage therethrough; a core member located within said passage, a portion of the surface of said core member being outwardly. convex; a flexible sleeve in said housing and surrounding said core member, said sleeve having an inwardly convex portion extending inwardly'into engagement'with said convex portion of said core member when contracted by fluid pressure, the curvature of said convex portion of said sleeve creating a sealing force in said sleeve said core member; and means for admitting fluid under pressure into a space in said housing surrounding said sleeve, the force exerted by the curvature of said sleeve cooperating with the pressure of said fluid in said space to maintain said sleeve in sealing engagement with said core member to prevent a flow of fluid through said passage.

17. In a valve device, the combination of; a housing having an inlet and outlet for a fluid passage therethrough, a portion of the wall of said passage being outwardly concave; a core member in saidpassage disposed substantially opposite to said concave portion of said passage: a flexible sleeve surrounding said core member, said sleeve being movable from a first position in which it engages said core member to form a seal therewith closing said passage to a second position in which it is outwardly extended to open said passage and in which its inner surface is substantially parallel throughout its length to said concave portion of said passage; and means communicating with said outlet for admitting fluid under pressure into engagement with the external surface of said sleeve member to cause it to occupy said first position.

18. In a valve device, the combination of a 2,247,353 casing having an inlet, an outlet, and'a passage therebetween; a seat-member within said casing; a closure member within said casing comprising a slack flexible sleeve attached at its ends within said casing and normally engaging a P ripheral portion of said seat member to close said passage,

said closure member being disengageable from said seat member when the fluid pressure in said 

